| Abstract: | 在自然界中，鐵通常都以Fe2+、Fe3+之化合物的狀態存。而高鐵酸鉀較為罕見，其中鐵以氧化態Fe6+的形式存在，為目前能製備出最常見且較穩定之高鐵氧化態之化合物。高鐵酸鉀經研究證明能有效去除水中之有機物、重金屬、細菌和藻類。且高鐵酸鉀分解之產物Fe(OH)3還具有良好的絮凝作用，可吸附有害物質和懸浮固體。做為水處理劑集氧化、殺菌、吸附、絮凝、助凝、脫色、除臭等功能於一體，在水處理方面顯示出良好的應用前景。然而市面上高純度之高鐵酸鉀售價昂貴，導致其應用價值較低。 本研究利用次氯酸氧化法，探討改變製備參數對高鐵酸鉀產率及純度之影響，研究改變參數主要分三部分。第一部分，固定次氯酸鈉溶液、硝酸鐵水合物用量、反應溫度、反應時間，發現氫氧化鈉最佳用量為12 g。第二部分，固定次氯酸鈉溶液、氫氧化鈉用量、反應溫度、反應時間，發現硝酸鐵水合物最佳用量為4 g。第三部分，固定次氯酸鈉溶液、氫氧化鈉、硝酸鐵水合物用量，發現最佳反應溫度、時間為40℃、40分鐘。
Ferrous (II) and ferric (III) are general iron oxides which exist in nature. However, potassium ferrate (VI), K2FeO4, is an unusual iron oxide that its oxidation state of iron is +6. It is one of common ferrate which is more stable and easy to be synthesized. Potassium ferrate (VI) is confirmed that it is valid to remove organic compounds, heavy metal, bacteria, and alga in water. When K2FeO4 reacts in water, it will be reduced to Fe(OH)3. Fe(OH)3 have good flocculation that can adsorb harmful substances and suspend solids in water. Potassium ferrate (VI) is good water treatment agent that widely applied for oxidization, adsorption, coagulation, disinfection, and deodorization. However, high purity potassium ferrate is less used due to its high price. In this study, the hypochlorite oxidation method is applied to prepare K2FeO4. The influences of synthesis parameters on the yield and purity of K2FeO4 are investigated. Changing of synthesis parameters is divided into three parts. In first part, the amounts of NaClO and Fe(NO3)3∙9H2O, the reaction temperature, and the reaction time are fixed. The optimum amount of NaOH is 12 g. In second part, the amounts of NaClO and NaOH, the reaction temperature, and the reaction time are fixed. The optimum amount of Fe(NO3)3∙9H2O is 4 g. In third part, the amounts of NaClO, NaOH, and Fe(NO3)3∙9H2O are fixed. The optimum reaction temperature and time are 40℃ and 40 min, respectively. |
